Building, restoration, and repair with epoxy

Effect of Surface Treatment on Adhesion to Metals

By Brian Knight

We have performed tens of thousands of adhesion tests over the years and many of these tests were done on metal surfaces. Below is a summary of tests done on a variety of metal surfaces and done with a variety of surface preparations. As you look at the chart, notice the surface preparation that gives the highest number.

All the tests shown below were performed using a PATTI (pneumatic adhesive tensile test instrument) meter. We chose this test method as our default adhesion test method about 14 years ago because it yields consistent results, is relatively easy to perform, and is economical. The results shown below show the tensile strength of a glue-joint. Not all joints are stressed in tension, so consider the data to be comparative, not a specification.

Most of the tests were done with WEST SYSTEM® 105/205 or 105/206. Most were allowed a two-week room temperature cure before the test was performed.